Best Of

Another option might be to create a beast mode to rank each traveler and then use subtotals to collapse the rows for the travelers whose rank is greater than 25. Assuming you have a field named `Traveler` and a field named `Spend`, first create a beast mode called `Top 25 Ranking`

— Rank Each Traveler up to 25 and then place remaining in 26
CASE 
WHEN SUM(COUNT(DISTINCT `Traveler`)) OVER (ORDER BY sum(`Spend`) DESC) <= 25 

  THEN SUM(COUNT(DISTINCT `Traveler`)) OVER (ORDER BY sum(`Spend`) DESC)

  ELSE 26

END

Place the Top 25 Ranking on the card, along with Traveler and Sum of Spend

Next, in the properties menu to go Subtotal Rows and select "Show subtotal rows" and "Suppress single item subtotals". By adding Subtotals you can now expand and collapse the Top 25 Ranking to hide the Travels who didn't make the Top 25.

Finally, when I tried this on some sample data I noticed that the subtotal for ranking #26 was summing up to be the same as the total so I created another beast mode called `Spend By Traveler` so that the spend numbers would subtotal correctly:

SUM(SUM(`Spend`)) OVER (PARTITION BY `Traveler`)

If this works for you then you should end up with a table that displays 26 rows, with the last row that can show/hide the travelers who didn't make the top 25. I was testing with a smaller dataset so I made a Top 5 version

Collapsed/Expanded Views: